Electrical wiring system and ejectable devices therein

ABSTRACT

An electrical wiring system for multistory buildings, embodying feed-wires extending vertically through the several stories of the buildings with electrical devices, such as outlet receptacles, switches, etc., in housings connected in circuit with said feed wires in substantial vertical alignment, and each of said devices incorporating a protective safety-fuse element therein, which upon rupture is ejected from its housing to render it easily discernible for replacement. Thereby the need for conventional panel boards with circuit-breakers or fuses therein, at different levels of the buildings, and in individual apartments, may be eliminated.

United States Patent Alvin S. Gittin 11717 Larry Road, Fairfax, Va.20230; Ralph E. McDonald, Washington, D.C. 867,024

Oct. 16, 1969 Oct. 12, 1971 said Gittin, by said McDonald lnventorsAppl. No. Filed Patented Assignee ELECTRICAL WIRING SYSTEM AND EJECTABLEDEVICES THEREIN 6 Claims, 10 Drawing Figs.

US. Cl 317/40 A, 307/42, 307/147, 315/361 Int. Cl 1-102h 5/04 Field ofSearch 307/42,

[56] References Cited UNITED STATES PATENTS 2,677,010 4/1954 Robinson307/147 3,408,537 10/1968 Wiley 307/42 X 3,432,677 3/1969 Meyers 307/147X 3,450,948 6/1969 Gerlach et al. 317/40 X Primary Examiner-James D.Trammell Attorney-Samuel Lebowitz PATENTEDnm 12 I971 SHEET 1 OF 2INVENTORS ALVIN S. GITTIN RALPH E. MCDONALD ATTORNEY PATENTEDBET 12 :91]3, 6 1 2 953 SHEET 2 c5 2 .M ,.7 H Hr A 4 I INVENTORS i ALVIN S. GITTINr g I F|G 10 RALPH E. Mc DONALD 4 H BY h Rd ATTORNEY ELECTRICAL WIRINGSYSTEM AND -EJECTABLE DEVICES TIIEREIN This invention relates to anelectrical wiring system for multistory buildings and more particularlya system adaptable to the wiring of modern high-rise buildings, whicheliminates the need for panel boards at the different levels of thebuildmg.

It is the object of the present invention to provide an electricalwiring system for multistory buildings which is economical in initialconstruction, as well as maintenance, and which is characterized by manysafety features which are more than adequate to comply with the minimumcode requirements for providing adequate power for anticipated loads.

It is another object of the invention to provide an electrical wiringsystem for multiple story buildings which embodies a plurality of feedwires extending in vertical directions from the service entrance box,with electrical devices accommodated in housings which are inserted inthe vertical fe'ed wires in substantial vertical alignment, with suchdevices incorporating self-contained safety fuses for the protection ofthe wiring system and the electrical units attached thereto, withoutneed for individual panel boards with circuit breakers or safety fusestherein at the different levels of the building for distribution of theelectric power therefrom.

The provision of individual fusible safety links in the electricaldevices wired into the vertical feeders, with provision for theautomatic ejection of the devices from their housings upon the ruptureof the fusible links, makes possible the easy detection of any fault inthe system when such is caused either by a short circuit of anyappliance which may be connected in the system, or by a high resistancefault which presents a tire hazard and which eventually leads to aconflagration. This reduces maintenance costs in the courseoftroubleshooting.

The wiring system in accordance with the invention, with. the electricaldevices such as outlet receptacles and switches arranged insubstantially vertical alignment, results in tremendous economies overpresent systems of wiring. Thus, not only are the costs of the panelboards and the connections thereto eliminated, but the amount ofmaterial and labor which is entailed in the stringing and connecting thefeed lines from the panel boxes in horizontal and vertical directionsaround doorways and through the vertical studs, is reducedsubstantially, resulting in great economies.

Furthermore, the increased safety accruing from the provision of fusiblelinks at each electrical device, such as outlet receptacles andswitches, reduces fire hazards as well as more serious injuries arisingfrom the insertion of foreign metal objects within the openings of theoutlet receptacles. The individual and immediate blowing of a safetyfuse in one outlet receptacle excludes black-outs which normally arecaused by the blowing of a fuse in a panel board, as usually occurs whena fault arises in any branch circuit or feeder line, which incapacitatesthese lines and all electrical units connected thereto.

The proximity and the distribution of the fusible individual linksforming part of each individual electrical device connected to thevertical feeders and the iinmediate rupture thereof, would greatlyreduce the incidence of fire resulting from a high-resistance fault inthe wiring system which engenders heat and ultimate burning, withoutnecessarily actuating the fuse or circuit breaker in the panel box, ashas been the case heretofore. Furthermore, the fault is more easilylocated in proximity to the ejected switch or outlet.

The provision of safety outlets throughout the wiring system eliminatesthe possibility of overloading any part of the wiring system.

It is another object of the invention to provide rugged and economicalelectrical devices, such as outlet receptacles and switches, which maybe fitted with safety fuses of different capacities in dependence uponthe circuit needs, and the failure of which may be indicated readily sothat another operative device may be substituted therefor to reestablishthe necessary circuit conditions upon the removal of the faultyelectrical unit therefrom, the location of which may be determined withrelative definiteness by virtue of the proximity of the ejected deviceto the faulty electrical unit or wiring.

The electrical devices in accordance with the invention, embodyinghousings for ejectable outlet receptacles and switches, also may beinstalled in existing wiring systems to realize all of the advantagesaccruing from these devices even though they may not form components ofvertical wiring arrangements.

While outlet receptacles for attachment plugs, as well as switches, havebeen provided heretofore with fuse devices therefor, as described inPat. Nos. 2,086,861, July 13, 1937, and 2,256,716, Sept. 23, 1941, nonehas incorporated the advantageous features as disclosed herein, andespecially the feature of the automatic ejection of the device from itshousing upon the blowing of the fusible link.

Other objects and purposes will appear from the detailed description ofthe invention following hereinafter, taken in conjunction with theaccompanying drawings, wherein FIG. 1 is a perspective view of a duplexoutlet receptacle for attachment plugs, each incorporating a safetyfuse, and the lower one shown in ejected position arising from ruptureof the fusible link in the interior thereof;

FIG. 2 is a perspective view of the outlet receptacle adapted to beinserted interchangeably in the casing provided therefor, which is wiredinto the vertical feeders extending through a plurality of stories ofthe building;

FIG. 3 is a perspective view of a toggle switch adapted to be insertedinto a housing therefor and which is wired into the vertical feedersextending vertically through the several stories of the building for thecontrol of overhead ceiling lights or other electrical units;

FIG. 4 is a front elevation of the casing of a duplex outlet receptacleadapted to be mounted within an outlet box mounted within the buildingwall and which is covered by the ornamental plate shown in FIG. 1, withthe sockets therein for receiving the ejectable outlet receptaclebodies;

FIG. 5 is a horizontal sectional view along line 55 of F IG.

FIG. 6 is a horizontal sectional view of the outlet receptacle bodyshown in FIG. 2, showing the arrangement of the contact terminalstherein;

FIG. 7 is a view similar to FIG. 6 showing the arrangement of the partsupon the blowing of the fuse within the outlet receptacle body arisingfrom a short circuit or other fault in the electrical unit which isadapted to be connected to the outlet body by means of an attachmentplug;

FIG. 8 is a vertical sectional view along line 8-8 of FIG. 6 l with thefuse mounting shown in solid lines when the outlet body is operative,and with the fuse mounting in dotted lines upon the rupture of the fuseas indicated in FIG. 7;

\ FIG. 9 is a perspective view of a structural detail for supporting thefusible link shown in H08. 6, 7 and 8; and

FIG. 10 is a schematic view of a multistory building showing the feedwires extending upwardly through the several stories, with electricaldevices wired therein in substantially vertical alignment at laterallydisplaced points of the building, for example, casings for mountingoutlet receptacles for attachment plugs in some of the feed wires, whileothers are wired with housings for receiving ejectable control switchesin accordance with the invention.

In FIG. 10 of the drawings a multiple story building B is shownschematically, having vertical feed wires 1 and 2 extendingupwardlythrough the several floors F and into which are wired electricaldevices 3 and 4, respectively.'These feed wires are run from a serviceinlet from a main panel board at a lower level of the building and aredistributed around the building to provide housings 3 for outletreceptacles 0 in substantially vertical alignment at the several levelsof the building for connection of floor lamps, table lamps, or otherelectrical units thereto. Another feeder 2 is designed to have connectedthereto at the different levels of the building, housings 4 for controlswitches S which are connected to overhead ceiling lights 11, and whichcontrol the operation of the latter. It is understood that thesevertical feeders 1 and 2 are illustrative of many which are spacedlaterally around the perimeter of the building and which extendvertically, to satisfy the need for switches and outlets for theelectrical units and appliances to satisfy the demands for electricpower in the building, in dependence upon the functional needs of thebuilding, whether it be for apartments, offices or the like.

The arrangement of the distribution of the wiring feeders is indicatedschematically in FIG. 10, which makes possible connection of theelectrical units thereto without need for any panel boards at thedifferent levels of the building which normally are provided withadequate circuit breakers in conformity with the requirements of theelectrical building codes. The latter are replaced by devices inaccordance with the invention which are connected to the verticalfeeders and which are fitted with the necessary safety devices whichfunction is normally performed by circuit breakers within the panel box.The devices in accordance with the invention meet these needs to adegree superior to that afforded by the conventional panel boxes, sothat the latter may be eliminated and realization may be had of theadvantages accruing from a system of wiring which need be run mainly invertical directions without minimum of wiring extending in horizontaldirections, with the consequent reduction in costs of labor andmaterials entailed in cutting through vertical studs and across doorwaysand other building components.

The electrical devices in accordance with the invention are illustratedin the remaining figures of the drawings, and FIG. 1 shows one of theduplex outlets which may be used interchangeably with single outlets,which are adapted to be wired into the vertical feeders 1 extendingthrough the building walls at laterally displaced points therealong.

As shown in FIGS. 1 and 4, the duplex outlet 3 may be formed of a casingof insulating material defined by a front wall 11, lateral walls l2, l2and a rear wall 14. The casing is preferably formed of molded plasticmaterial, such as Bakelite and may be reenforced by a metallic band 13extending across the vertical median of the rear face thereof, and whichextends transversely therefrom adjacent to the top and bottom edges ofthe casing and wherefrom it is bent in vertical directions to formmounting flanges 28 at the front of the casing. The mounting flanges 28are provided with slightly elongated slots 29 therein for receivingfastening screws 30 which engage threaded lugs formed in the outlet boxmounted within the building wall, which expedients are conventional andwell known in the art. In the case of the duplex outlet shown in FIG. 4,a threaded opening 34 is provided at the midportion of the front wallfor receiving a threaded bolt 32 for mounting an ornamental plate P inoverlying relation to the casing 3, as shown in FIG. 1.

The ornamental plate P above and below the fastening screw 32, isprovided with openings of the same contours as the socket 20 in thecasing and in overlying relation thereto for the insertion into thesockets of outlet bodies 0, the fronts of which are shown in FIG. 1 anda rear perspective view of which is shown in FIG. 2. These bodies areformed of any desired hard plastic material such as Bakelite and may beconstituted by upper and lower members 41 and 42 joined together along ahorizontal median plane 43. The outlet body is provided with openings40, 40 in the lateral walls thereof from which protrude parts of springdetent members M and M, described in greater detail below, which serveto latch the body 0 within its socket in the operative state of thefusible link therein, and which retract upon its rupture to permit thebody to be ejected automatically from its socket.

The components 41 and 42 of molded plastic may be formed with therequired passages and chambers for accommodating the circuit-makingelements of the outlet body when the same is inserted into one of thesockets in the casing shown in FIG. 4.

The top surface 44 of the body 0 is provided with a central lug orkeyway 47 of predetermined width which is limited by lateral recesses48, 48 extending to the rear wall 49 of the body. The bottom surface ofthe body 0 is plane while the lateral walls 46, 46' have a curvatureconforming to the lateral walls 21 of the sockets 20. The latter areprovided with projections 17 at the junctions of the upper walls of thesockets with the lateral walls 21, leaving a gap or groove 18 betweenthe projections, which compels the insertion of the body 0 with theupper wall of the body always on top, which arises from theaccommodation of the keyway 47 within the groove 18. This structuralarrangement renders impossible the insertion of the body 0 in anupside-down position. The width of the keyway provides a reliableindication for the thermal rating of the fuse link in the body 0. Thus,if the housing 3 is wired to accommodate a load of 5 amps, groove 18therein is of a predetermined width which will receive a body 0 with alug 47 of corresponding width, or smaller, but which will block anoutlet body of greater capacity, such as l0 amps, in which case thekeyway 47 is wider.

The front of the body 0 is provided with vertical slots 51 and 52 ofunequal length and a rounded slot 53. Conductive terminals are providedon the interior of the body 0 in communication with each of the slots sothat those in communication with the slot 51 are connected to theneutral terminal of the distribution system, those connected to the slot52 are connected to the hot" side of the line, while the terminalcommunicating with the opening 53 leads to a grounding terminal.

The safety fuse is connected in series with the hot" side of the line sothat when any fault arises in the electrical unit which is plugged intothe outlet body 0 by way of the prongs of an attachment plug leadingfrom the electrical unit (not shown), through the vertical slots 51 and52, the fuse blows" and the outlet body 0 is automatically ejected fromits socket for a limited extent, as indicated for the lower body 0 shownin FIG. 1, to indicate which unit is faulty and requires disconnection.This does not affect the continuity of the power supply to the upperoutlet which is mounted in the casing 3.

The automatic ejection of the outlet body in response to a fault in theelectrical unit connected thereto, may be realized in many differentways, and the arrangement shown in FIGS. 5 to 9 is illustrative of manypossible arrangements for attaining for attaining this result.

The outlet casing 3 which is affixed within the outlet box in thebuilding wall (not shown), may be provided with its own ground, whilesupporting means for automatically ejecting the outlet body 0 upon theblowing" of the thermal fuse therein; Thus, the grounding strap 13extending vertically across the rear of the casing may be stamped with acircular opening 15 along a plurality of radial lines and the inner endsof the several radii 16 may be turned along curved lines to engage theouter end of a spiral spring 17 as clearly shown in FIG. 8.

Each outlet body is adapted to be inserted into its socket and latchedtherein following the compression of the spring as shown in FIGS. 5 and8, so that the spring exerts a resilient force to eject the body, whichforce is resisted by the spring detent members mentioned above, as longas the fusible link in the outlet body 0 is maintained in operativeposition. When the fuse blows, these spring detent members are releasedso that the ejecting spring 17' is free to exert its influence to ejectthe outlet body from its socket at least to a limited degree, as shownin the case of the lower body in FIG. 1, thereby to indicate the blowingof the fuse therein.

The casing shown in FIGS. 4 and 5 is designed to have the neutralconductor of the feed wire 1 connected thereto at screw 27 and the hotwire at screw 27 These screws are mounted in conductive members 25 and25', respectively, which terminate in contact terminals 26, 26' ofgenerally C- shaped allochiral relationship. The electric current isdesigned to pass from these terminals to the conductive terminals withinthe outlet body 0 disposed in the chambers in the latter and from therethrough the projecting prongs of an attachment plug connected to anelectric unit, which prongs are inserted into the electrical bodythrough slots 51 and 52.

As stated above, the outlet body is provided with spring detent memberson each side thereof which perform the dual function of completing theelectrical circuit between the wire terminals of the casing to theprongs of the attachment plug and at the same time function as balancedlatching members which effectively resist the force of the expulsionspring 17 as long as the thermal fuse is effective, but which isincapacitated both as an electric conductor and a latch by the blowingof the fuse.

Thus, as maybe seen in FIGS. 6 and 7, the metallic contact member M fromthe hot" side of the line is retained within the body of the outletreceptacle along the length 60 thereof, wherefrom it is bent inwardly atthe reentrant portion 61 in an inclined direction, and thereafter it isbent outwardly along a short straight length 63 to tip 64 wherefrom itis bent inwardly along a curved terminal portion 62. A metallicconducting piece 84 extends from length 60 of contact member M, to whichis soldered the base element of the fuse 80 at point 83. The fuse 80 isthreaded from point 83 through aligned openings 87 in the top and bottomflanges 86, 86' of a spacer I of insulating material (FIG. 9), beyondwhich the fusible element has a narrowed portion 81 which determines itsrating. The end of the fuse is affixed to the terminal connector 57seated within chamber 54 and with which cooperates a jaw of metallicmaterial in juxtaposed relation thereto for accommodating one of theprongs of the attachment plug which is inserted into the slot 52. I

The companion metallic detent member M, of generally similar contour atits outer end as is member M, is contained within the body 0. Theconfined end 70 of member M is retained within passages formed in thebody wherefrom the reentrant-portion 71 is bent inwardly and passestherefrom to the short straight portion 73 to the curved tip 74,wherefrom the member is curved at its terminal portion 72 with acurvature generally of C-shaped contour adapted to be accommodatedwithin the terminal 26 on the interior of the casing 3, and which isallochirally related to the terminal portion 62 of leaf spring member M.

When the outlet body 0 is in operative condition, the retainer member Iis disposed vertically, as shown in FIGS. 6 and 8, and the oppositeedges 85 of the intermediate wall 85 between flanges 86, are effectiveas fulcrum points for the metallic leaf springs M, m adjacent to' thebases of the reentrant portions which are adapted to be flexed from thepositions shown in solid lines in FIG. 6, to those shown in dotted linesas the body is inserted into the socket 20. The inner faces of thelateral walls of casing 22, 22 may be tapered in the direction ofinsertion of the body, as indicated on an enlarged scale in FIG. tofacilitate the flexing of the free curved ends 62, 72 of the metallicsprings M, m towards the interior of the body as the latter is movedinwardly. However, when the body 0 reaches its end position, the freeends of the springs M, M, which have been cammed towards the interior ofthe body, arrive opposite the contact terminals 26, 26' and are now freeto spring outwardly into the solid line positions shown in FIG. 6, atwhich time they assume a nested position within the terminals 26' and26, respectively, of the casing (FIG. 5). In this position the body isseated securely to receive the projecting prongs of an attachment plug,but is biased in a condition to be ejected if the fuse in the bodyshould blow. When this happens, the inclined straight lengths 61 and 71of the metallic springs M, M serve to cam the upper portion of theinsulating retainer I into the dotted line position shown in FIG. 8, sothat the normal resilience of the metallic springs M, M drives theportions of the conductors adjacent the curved tips 64 and 74 thereoffree of the outer walls of the body into the interior of the latterthrough openings 40, 40, as indicated in FIG. 7, so that spring 17 isfree to exert its force against the end of the body to eject it from thecasing to the limited extent indicated in FIG. 1. The ejection of thebody 0 at the lower end of the plate P does not affect the circuit ofthe electrical unit which may be connected to the upper body 0, so thatthere is no complete blackout in the room, as generally occurs when afuse blows" in a panel box. The partial ejection of the outletreceptacle body renders easy its removal from the socket for inserting areplacement. Even in the absence of a replacement, the concealedcontacts 26, 26' at the rear of the socket 20 minimizes any danger ofinjuries by accidental contact therewith. The extent of the ejectingmovement of the body may be controlled by the force of the spring andthe difference in length thereof between its compressed condition, asshown in FIGS. 5 and 8, and its freely extended position (not shown).

FIG. 8 also shows a grounding conductor 91 within the ground opening 53of outlet receptacle body 0, which may be connected to the rear face ofthe body and which terminates in a circular portion against which theinner end of spring 17 presses to eject the body when the fuse blows."The grounded terminal 91 thus communicates with the metallic strap 13and the attachment flanges 28 to constitute an effective ground for theoutlet when a grounded terminal is neces sary.

As stated above, while FIGS. 1 and 4 illustrate a duplex outletreceptacle, the casing 3 may be formed with a single socket 20 adaptedto house a single outlet receptacle body. Such a casing may be used tohouse and eject a control toggle switch S, as shown in FIG. 3, which isprovided with spring detent members M, M'of a construction similar tothat described in connection with the outlet receptacle 0. The casingsfor the switches may be of the duplex type to accommodate a pair of suchswitches if such are desirable. Of course, the switch housings 4 for theejectable switches S, while the similar construction as the housings forthe outlet receptacles O, are positioned at higher levels above thefloor as shown in FIG. 10.

It is understood that the casings 3 and 4 for outlet receptacles orswitches may be substituted for conventional units in outlet boxes inexisting wiring systems, to attain the advantages of the instantinvention.

We claim: 1. An electrical wiring system for a multistory building,comprising:

a. an internal electrical service inlet at a low level in the interiorof said building,

b. a plurality of vertical feed-wires branched from and extendingupwardly from said service inlet through the several stories of saidbuilding.

c. electrical devices and casings therefor connected to said feed-wiresat a plurality of said stories in substantially vertical alignment andd. means including a thermal overload safety fuse of predeterminedrating at each of said electrical devices responsive to the faultyoperation of any electrical unit connected to the individual device, forejecting the latter at least partially from its casing, thereby todisconnect said electrical unit from the system without causing failureof the remainder of the system or affecting the other electrical unitsconnected thereto, while visibly indicating the location of the faultyunit.

2. A system as set forth in claim I, wherein said electrical devices areoutlet plug receptacles.

3. A system as set forth in claim 1, wherein said electrical c. outletplug receptacles connected to said feed-wires at a plurality of saidstories in substantially vertical alignment, and d. a thermal overloadsafety fuse of predetermined rating at each of said outlet plugreceptacles responsive to the faulty operation of any electrical unitconnected to the individual receptacle, for disconnecting saidelectrical unit 1 from the system without causing failure of theremainder of the system or affecting the other electrical unitsconnected thereto.

5. A system as set forth in claim 4, wherein said outlet plugreceptacles at the plurality of said stories are of the duplex type withcasings therefor, each provided with ejecting means for each receptaclefrom the casing containing it, in response to the rupture of the safetyfuse, to locate readily the faulty electrical unit.

6. An electrical wiring system for a multistory building, comprising a.an electrical service inlet at a low level of said building,

b. a plurality of feed-wires branched from and extending upwardly fromsaid service inlet through the several stories of said building,

c. electrical switches and casings therefor connected to said

1. An electrical wiring system for a multistory building, comprising: a.an internal electrical service inlet at a low level in the interior ofsaid building, b. a plurality of vertical feed-wires branched from andextending upwardly from said service inlet through the several storiesof said building. c. electrical devices and casings therefor connectedto said feed-wires at a plurality of said stories in substantiallyvertical alignment and d. means including a thermal overload safety fuseof predetermined rating at each of said electrical devices responsive tothe faulty operation of any electrical unit connected to the individualdevice, for ejecting the latter at least partially from its casing,thereby to disconnect said electrical unit from the system withoutcausing failure of the remainder of the system or affecting the otherelectrical units connected thereto, while visibly indicating thelocation of the faulty unit.
 2. A system as set forth in claim 1,wherein said electrical devices are outlet plug receptacles.
 3. A systemas set forth in claim 1, wherein said electrical devices are controlswitches.
 4. An electrical wiring system for a multistory building,comprising: a. an electrical service inlet at a low level of saidbuilding, b. a plurality of feed-wires branched from and extendingupwardly from said service inlet through the several stories of saidbuilding, c. outlet plug receptacles connected to said feed-wires at aplurality of said stories in substantially vertical alignment, and d. athermal overload safety fuse of predetermined rating at each of saidoutlet plug receptacles responsive to the faulty operation of anyelectrical unit connected to the individual receptacle, fordisconnecting said electrical unit from the system without causingfailure of the remainder of the system or affecting the other electricalunits connected thereto.
 5. A system as set forth in claim 4, whereinsaid outlet plug receptacles at the plurality of said stories are of theduplex type with casings therefor, each provided with ejecting means foreach receptacle from the casing containing it, in response to therupture of the safety fuse, to locate readily the faulty electricalunit.
 6. An electrical wiring system for a multistory building,comprising a. an electrical service inlet at a low level of saidbuilding, b. a plurality of feed-wires branched from and extendingupwardly from said service inlet through the several stories of saidbuilding, c. electrical switches and casings therefor connected to saidfeed wires at a plurality of said stories in substantially verticalalignment, d. a thermal overload safety fuse of predetermined rating ateach of said electrical switches responsive to the faulty operation ofany electrical unit connected to the individual switch in closeproximity to the latter for control thereby, and e. ejecting means foreach switch from the casing containing it, in response to the rupture ofthe safety fuse to locate readily the fault in the electrical system inclose proximity to the ejected switch.